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Create <sect3> in the functions-xml section

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This is a small change so that a new XMLTABLE sect3 can be added easily
later.

Author: Craig Ringer
Discussion: https://postgr.es/m/CAFj8pRAgfzMD-LoSmnMGybD0WsEznLHWap8DO79+-GTRAPR4qA@mail.gmail.com
This commit is contained in:
Alvaro Herrera 2017-03-01 19:27:24 -03:00
parent 231f48796b
commit 4461a9bfd1
1 changed files with 56 additions and 48 deletions
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104
doc/src/sgml/func.sgml
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@ -10328,10 +10328,6 @@ SELECT xml_is_well_formed_document('<pg:foo xmlns:pg="http://postgresql.org/stuf
<sect2 id="functions-xml-processing">
<title>Processing XML</title>
<indexterm>
<primary>XPath</primary>
</indexterm>
<para>
To process values of data type <type>xml</type>, PostgreSQL offers
the functions <function>xpath</function> and
@ -10339,39 +10335,46 @@ SELECT xml_is_well_formed_document('<pg:foo xmlns:pg="http://postgresql.org/stuf
expressions.
</para>
<sect3 id="functions-xml-processing-xpath">
<title><literal>xpath</literal></title>
<indexterm>
<primary>XPath</primary>
</indexterm>
<synopsis>
<function>xpath</function>(<replaceable>xpath</replaceable>, <replaceable>xml</replaceable> <optional>, <replaceable>nsarray</replaceable></optional>)
</synopsis>
<para>
The function <function>xpath</function> evaluates the XPath
expression <replaceable>xpath</replaceable> (a <type>text</> value)
against the XML value
<replaceable>xml</replaceable>. It returns an array of XML values
corresponding to the node set produced by the XPath expression.
If the XPath expression returns a scalar value rather than a node set,
a single-element array is returned.
</para>
<para>
The function <function>xpath</function> evaluates the XPath
expression <replaceable>xpath</replaceable> (a <type>text</> value)
against the XML value
<replaceable>xml</replaceable>. It returns an array of XML values
corresponding to the node set produced by the XPath expression.
If the XPath expression returns a scalar value rather than a node set,
a single-element array is returned.
</para>
<para>
The second argument must be a well formed XML document. In particular,
it must have a single root node element.
</para>
<para>
The second argument must be a well formed XML document. In particular,
it must have a single root node element.
</para>
<para>
The optional third argument of the function is an array of namespace
mappings. This array should be a two-dimensional <type>text</> array with
the length of the second axis being equal to 2 (i.e., it should be an
array of arrays, each of which consists of exactly 2 elements).
The first element of each array entry is the namespace name (alias), the
second the namespace URI. It is not required that aliases provided in
this array be the same as those being used in the XML document itself (in
other words, both in the XML document and in the <function>xpath</function>
function context, aliases are <emphasis>local</>).
</para>
<para>
The optional third argument of the function is an array of namespace
mappings. This array should be a two-dimensional <type>text</> array with
the length of the second axis being equal to 2 (i.e., it should be an
array of arrays, each of which consists of exactly 2 elements).
The first element of each array entry is the namespace name (alias), the
second the namespace URI. It is not required that aliases provided in
this array be the same as those being used in the XML document itself (in
other words, both in the XML document and in the <function>xpath</function>
function context, aliases are <emphasis>local</>).
</para>
<para>
Example:
<para>
Example:
<screen><![CDATA[
SELECT xpath('/my:a/text()', '<my:a xmlns:my="http://example.com">test</my:a>',
ARRAY[ARRAY['my', 'http://example.com']]);
@ -10381,10 +10384,10 @@ SELECT xpath('/my:a/text()', '<my:a xmlns:my="http://example.com">test</my:a>',
{test}
(1 row)
]]></screen>
</para>
</para>
<para>
To deal with default (anonymous) namespaces, do something like this:
<para>
To deal with default (anonymous) namespaces, do something like this:
<screen><![CDATA[
SELECT xpath('//mydefns:b/text()', '<a xmlns="http://example.com"><b>test</b></a>',
ARRAY[ARRAY['mydefns', 'http://example.com']]);
@ -10394,27 +10397,31 @@ SELECT xpath('//mydefns:b/text()', '<a xmlns="http://example.com"><b>test</b></a
{test}
(1 row)
]]></screen>
</para>
</para>
</sect3>
<indexterm>
<primary>xpath_exists</primary>
</indexterm>
<sect3 id="functions-xml-processing-xpath-exists">
<title><literal>xpath_exists</literal></title>
<indexterm>
<primary>xpath_exists</primary>
</indexterm>
<synopsis>
<function>xpath_exists</function>(<replaceable>xpath</replaceable>, <replaceable>xml</replaceable> <optional>, <replaceable>nsarray</replaceable></optional>)
</synopsis>
<para>
The function <function>xpath_exists</function> is a specialized form
of the <function>xpath</function> function. Instead of returning the
individual XML values that satisfy the XPath, this function returns a
Boolean indicating whether the query was satisfied or not. This
function is equivalent to the standard <literal>XMLEXISTS</> predicate,
except that it also offers support for a namespace mapping argument.
</para>
<para>
The function <function>xpath_exists</function> is a specialized form
of the <function>xpath</function> function. Instead of returning the
individual XML values that satisfy the XPath, this function returns a
Boolean indicating whether the query was satisfied or not. This
function is equivalent to the standard <literal>XMLEXISTS</> predicate,
except that it also offers support for a namespace mapping argument.
</para>
<para>
Example:
<para>
Example:
<screen><![CDATA[
SELECT xpath_exists('/my:a/text()', '<my:a xmlns:my="http://example.com">test</my:a>',
ARRAY[ARRAY['my', 'http://example.com']]);
@ -10424,7 +10431,8 @@ SELECT xpath_exists('/my:a/text()', '<my:a xmlns:my="http://example.com">test</m
t
(1 row)
]]></screen>
</para>
</para>
</sect3>
</sect2>
<sect2 id="functions-xml-mapping">